Ive been trying to research this and not getting the answers im looking for. Is it worth getting those coolers that is offered on Genos Garage for the nv5600? I dont tow much weight when i do to atleast for now. Once in a while i might tow 10k but thats in a blue moon. I am going to be changing fluids soon and will add the extra quart or two and just want to know if it really is worth it. Also im hearing different things about fluids and shifting smoother. Some say royal purple and other amsoil or redline. Any input on thatThanks

adding the coolers is a personal opinion, the issue you have is that the fluid is not actively cooled, just passively via the air around the trans.I would add them only because it will increase fluid capacity, especially if you live in a warmer climate.do some searching on the CF, i read somewhere where someone was using non Mopar fluid and it fixed his hard shifting issues.

Even though i wont tow a lot of weight. I will be towing to Vegas and Phoenix and Bakersfield during summer months and it gets hott out here in southwest. From the research i did i read that some ppl saw a drop of like 45 degrees or so. Wouldnt that be part of having extra fluid and that the temp sensor for the gauge is in the cooler itself? Im so stuck on this i dont know what to do

I have a set of Fast Coolers sitting in my garage waiting to install on my NV4500. Just cant seem to get around to installing them but I have good intentions. I wanted them because I did quite a bit of research when I was looking at buying a 5th wheel and found that running the Fast Coolers can lower the fluid temp considerably, and allow for a couple more quarts of volume as well. If you tow then I feel that anything you can do to help keep the fluid temps under control is very important. Not only for fluid life but because of the damage which can occur when the fluid gets to hot while towing. Remember that to rebuild the NV5600 is around $3500 minimum. Thats a lot of money. You see guys running around with Mag-Hytec differential covers all the time and the Mag-Hytec's real reason is for the additional fluid capacity.....but then again, everyone can see that money spent on the differential where as the tranny coolers are hidden.In saying that, I also understand that both the NV5600 and the NV4500 respond very positively to running one quart over the max fill hole capacity. That means getting the extra fluid in there through the shifter hole. But regarding the extra quart, the NV5600 should always run an extra quart over because the factory fluid level is to low for proper lubrication. The NV5600 can run just about any fluid brand as long as its the right viscosity weight where as the NV4500 must run factory lube. I've heard of guys using friction modifier in the NV5600 too which supposedly helps with shifting, but that would be up to you. So my opinion is, yes, get the coolers. I'm not sure Geno's still sells the Fast Coolers but you can get them directly from Fast Coolers or Geno's sells some other brand thats supposed to be nice too.

I have a set of Fast Coolers sitting in my garage waiting to install on my NV4500. Just cant seem to get around to installing them but I have good intentions. I wanted them because I did quite a bit of research when I was looking at buying a 5th wheel and found that running the Fast Coolers can lower the fluid temp considerably, and allow for a couple more quarts of volume as well. If you tow then I feel that anything you can do to help keep the fluid temps under control is very important. Not only for fluid life but because of the damage which can occur when the fluid gets to hot while towing. Remember that to rebuild the NV5600 is around $3500 minimum. Thats a lot of money. You see guys running around with Mag-Hytec differential covers all the time and the Mag-Hytec's real reason is for the additional fluid capacity.....but then again, everyone can see that money spent on the differential where as the tranny coolers are hidden. In saying that, I also understand that both the NV5600 and the NV4500 respond very positively to running one quart over the max fill hole capacity. That means getting the extra fluid in there through the shifter hole. But regarding the extra quart, the NV5600 should always run an extra quart over because the factory fluid level is to low for proper lubrication. The NV5600 can run just about any fluid brand as long as its the right viscosity weight where as the NV4500 must run factory lube. I've heard of guys using friction modifier in the NV5600 too which supposedly helps with shifting, but that would be up to you. So my opinion is, yes, get the coolers. I'm not sure Geno's still sells the Fast Coolers but you can get them directly from Fast Coolers or Geno's sells some other brand thats supposed to be nice too.

I run a fan operated trans cooler for my auto. Not same - but same principle. One of my best mods - rarely have to worry about tranny temps - regardless of where I am.